1881.] TRANSACTIONS. 31 



of the plants coimnonly found in houses, a medium temperature 

 is the best. A common living-room whicli is kept at a lieat of 

 seventy degrees or more till ten or eleven o'clock every evening, 

 has a great deal higher average temperature than a common 

 greenhouse. My largest greenhouse has not averaged so high 

 as sixty-five degrees for six hours in the day since last October, 

 while the night temperature has averaged from iifty to Hfty-two 

 degrees. Those of you who have visited it, can judge whether 

 the temperature is such as to produce liealthy plants. 



The reason why plants are injured by such a high temperature 

 in the night, is, that the heat stimulates the plants to try to grow 

 wlien they lack one of tlie most essential conditions of growth, 

 and tliat is light ; and they grow weak and spindling. If possi- 

 ble, the temperature should be at least ten or lifteen degrees 

 lower while it is dark. This may be attained by drawing a 

 curtain between tlie plants and the room. In a bay window this 

 can be done very easily. Of course it is necessary to be careful 

 that in cold nights the temperature does not get low enough to 

 freeze the plants. 



A bay window in a dining-room which is heated from adjoin- 

 ing rooms, and which is allowed to get as low as fifty-live degrees 

 at night is nearly as good as a conservatory which has no over- 

 head light. 



There are very vague notions about tlie giving of fresh air to 

 plants. And plants in sitting-rooms and parlors are often injured 

 by this giving of fresh air as it is called. When the room is 

 swept, the windows and perhaps the doors too, are thrown wide 

 open to let out the dust, and because the fresh air is so good for 

 plants they are left open till the tender ones are fairly chilled. 

 And then people wonder why they have such poor luck with 

 plants? But it is no wonder! 



It should always be borne in mind that no sudden changes in 

 the temperature should be made. Nature does it just right. And 

 how beautiful it is ! First, the slowly increasing light awakens 

 the plants from their nightly slumber, gradually arousing more 

 and more their dormant energies, till the heat of noonday; and 

 then as gradually quieting down to their evening rest, till the 

 sun goes down and the darkness comes on. 



A conservatory sliould be so constructed that some means of 

 ventilation is easily accessible ; and it should be where the cold 

 air of Winter will not blow directly upon the plants. The mer- 

 cury in a shady place in a conservatory ought never to rise above 

 70 degrees during the cold weather. As long days come on, and 

 growth becomes more vigorous, 75 or 80 degrees would be permis- 

 sible, but at night it should always be kept 15 or 20 degrees 

 cooler. 



